In general, wipers are used to remove excess water from transparencies such as automotive windshields and rear windows. It is known that extreme cold hardens the material of the wipers and/or freezes moisture resulting in the wiper sticking to the windshield and/or window. At the present time there are available automotive windshields and rear windows having facilities to heat the rest area or rest position of the wiper to soften the material of the wiper and/or to melt frozen moisture between the wiper and the windshield and/or rear window so that the wiper is free to move when the wiper motor is energized.
U.S. Pat. No. 4,109,133 teaches a rear window for an automobile having at an upper portion thereof resistance-heating wires for electrically heating the window. A window wiper is provided to sweep the window. In the wiper rest area or position, the window is provided with a heating wire to heat the rest area to free the wiper when frozen to the window. The width of the heated area in contact with the wiper is increased by providing the heating wire with sinusoidal undulations. U.S. Pat. No. 4,513,196 teaches a heatable windshield having two zones each having a plurality of spaced wires; one zone for rapid heating, the other for slow heating. The wires of each zone are sized to provide each zone with the different heating rate.
U.S. Pat. No. 4,971,848 discloses a heatable windshield having a plurality of fine conductive wires in the vision area and an increase in the number of wires in the lower portion to heat the wiper rest area or wiper rest position. The conductive wires are provided by depositing an electrically conductive enamel on the glass and heating the enamel to melt the enamel to the glass. Patentschrift 150 979 discloses a rear window heating system that also includes a plurality of spaced conductors in the vision area of the window and reduction in the space between the conductor in the end-of-travel position of the wiper blade. The spaced conductors are applied by screen printing a conductive heat setting material and thereafter firing the material to set it to the glass.
U.S. Pat. No. 4,373,130 also discloses a windshield having a heatable wiper rest area. The heatable area includes an electric heating resistance member between the inner and outer glass panes of the windshield or on outer surface of the inner pane of a laminated windshield. An opaque layer is disposed either on the inner or outer surface of the outer pane. When the resistance member is mounted on the outer surface it is positioned between an opaque member that is heat conductive and a member close to the outer surface of the pane that is less heat conductive than the opaque member. The heating member may be a plurality of conductors or a continuous metal or semiconductor layer.
European Patent Application 0 625 422 A1 discloses a heatable windshield having a plurality of closely spaced conductive strips on an enamel layer on the inside surface of the outer pane to heat the windshield wiper area. The strips are applied by screen printing silver on the decorative edge and thereafter heating the silver to set the strips. U.S. patent application Ser. No. 07/733,785 filed in the name of Harry S. Koontz on Jul. 22, 1991, for Coated Windshield With Special Heating Circuit For Wiper Arm Storage Area discloses a heatable windshield having a heatable member e.g. an electroconductive coating and bus bars spaced from one another at the lower portion of the windshield to heat the wiper rest area.
U.S. Pat. No. 4,910,380 discloses a motor vehicle window having a glass pane having an outer edge and a peripheral black obscuration band extending around the pane edge. The band is formed of a coating-deposited black conductor capable of generating heat when an electric current is passed through it. The black conductor made of frit that is silk screened onto the glass and fired to set the conductor to the glass may be mounted on a black non-conductive member or within a spaced non-conductive member. The black conductive member may be used to heat the wiper rest position on the window.
The above patents/patent application discuss techniques for heating windshield and/or rear window wiper rest areas. The techniques disclosed therein have drawbacks and/or limitations. More particularly, when the heating element or member is applied to the glass or a component of a laminated windshield, any defects in the heating element require the glass or component to be scraped or reworked; both options are expensive.
As can be appreciated it would be advantageous to provide a heating system e.g. a system for heating wiper rest area or wiper rest position of an automotive transparency, and method for making and using same that does not have the drawbacks or limitations of the presently available systems and methods.